This invention relates in general to automatically locking safety belt retractors of the type having a programmed pawl engagement, and more specifically, to a means for controlling the operation of a programming pawl employed in such retractors.
Emergency locking safety belt retractors are currently in wide use in automotive vehicles for storing safety belt webbing when not in use, and for restraining passengers in their seats by locking safety harness associated webbing wound on the retractor against protraction therefrom when a vehicle emergency condition is experienced. Typically, a vehicle inertia sensor means is employed to sense the emergency condition and to actuate a locking bar or pawl which engages with ratchet wheels provided on sides of the belt storage spool to prevent further belt protraction of the spool. The movement of the locking bar or pawl, into engagement with the spool associated ratchet wheels has been controlled by programming means which include a plastic programming ratchet mounted to the spool or spool axle and a programming pawl adapted to be actuated by the sensor means to engage the programming ratchet and be moved by rotation of the programming ratchet due to spool rotation whereby the programming pawl engages and lifts the locking bar or pawl into a metal-to-metal engagement with the spool ratchet wheels. Exemplary of such a safety belt retractor apparatus is that of the copending prior application Ser. No. 193,958 filed Oct. 6, 1980 now U.S. Pat. No. 4,371,128 and entitled "SEAT BELT RETRACTOR ASSEMBLY WITH PAWL MOUNTED PENDULUM".
It is the primary object of the present invention to disclose and provide a control means for a programming pawl of the type disclosed in said application Ser. No. 193,958 while will prevent operation of the spool locking means when the same is not required as when the safety belt is fully wound up on the retractor and is thus not in use. More specifically, it is an object of the present invention to disclose and provide a control means for controlling movement of the programming pawl relative to the programming ratchet under influence of the associated inertia sensor wherein the control means is simply and economically incorporated into the programming pawl and ratchet construction, where the assembly of such control means is automatically effected upon assembly of the programming pawl to the retractor apparatus and wherein the programming pawl operation is correlated to the position or condition of use of the spool, such positions or conditions corresponding to when the belt is not in use and belt webbing is fully wound up on the spool, when belt webbing is being protracted from the spool and when the webbing has been protracted enough to allow the associated safety belt or harness to be placed in a position of use.